I met with quite a few seasoned marathon runners, with dedication and discipline clocks in >500 FM and still counting. There is a platform called the “100 Marathon Club” (https://www.100mcnl.nl/) for the Dutch runners where it tracks the number of marathon one has accomplished, and the leaderboard.
Ben Mol is the organiser of this hassle free, BYOF “Bring Your Own Fuel”, RYOT “Record Your Own Time” twice a week marathon run. We finished this run in 4.45 hours. It was a 7 loop of 5.7 km + 2.5 km small loop.
meysrunningjourney.com 